Device for protecting structures from lightning-strokes.



W. BAJOHR.

DEVICE FOR PROTECTING STRUCTURES FROM LIGHTNING STROKES.

APPLICATION FILED FEB. 15, 1915.

1 ,1 62,437. Patented Nov. 30, 1915.

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\VILLIAM BAJOHR, OF ST. LOUIS, MISSOURI.

DEVICE FOR PROTECTING STRUCTURES FROM LIGHTNING-STROKES.

Specification of Letters Patent.

Patented Nov. 30, 1915.

Application filed February 15, 1%15. serial No. 8,202.

To all whom it may concern Be it known that I, lViLLniM BAJOHR, a

' citizen of the United States, residing at the city of St. Louis, State of Missouri, have invented a. certain new and useful Improvement in Devices for Protecting Structures from Lightning-Strokes, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, forming part of this application.

My invention relates generally to devices for protecting structures from lightning strokes, and refers specilically to an improvement in the arrangement of such devices for protection of chimneys or stacks.

The purpose of my invention is to increase the efliciency of such devices by certain improvements in the construction whereby any electrical discharge received by the device will be grounded without .injury to the structure upon which it is mounted and which it is designed to protect.

Other and further objects of my invention will be obvious or hereinafter pointed out.

One form of my improved device is illustrated in the accompanying drawings, in which- Figure 1 is an elevational view of a portion of a stack equipped with one form of my invention. Fig. 2 is a top View of the same. Fig. 3 is a detail illustrating the rod and conductor connection. Fig. l is a detail in section on the line 44 of Fig. 3.

Referring to the drawings in detail, it will be understood that 1 represents a stack, or other structure which it is desired to protect from lightning stroke. Mounted on the stack are the collecting rods 2, the number and spacing of which depend upon the size of the stack. These rods are firmly secured to the structure by any suitable supporting brackets 4. Arranged to cooperate with the rods are ground lines 5 which are preferably formed of suitable electrical conductive cables suitably supported on the structure by brackets, and well grounded in the earth at their lower extremities. Each of these ground lines is adapted to cooperate with a plurality of the rods 2, the number of these rods to each line depending, of course, upon the size of the stack. I prefer, however, to

- down gradually from limit the maximum number of rods to a ground line to three.

Encircling the upper portion of the stack isan equalizing conductor 6 which is in electrical connection with the ground lines by means of a plurality of lead cables 7 of elec trical conductive material. Each of the leads 7 springs from the lower terminus of a rod 2, and each of the rods 2 has electrical connection with both its associated lead and the equalizing conductor 6. The leads run the rods and equalizing conductor to the ground line, being connected to the latter at a point considerably below the equalizing conductor, the arrangement being such that there are no sharp turns or changes of direction in the conducting cable between the rods and the ground line. The purpose of thus doing away with such corners or changes of direction in the conductor is to obviate the likelihood of a charge leaving the conductor and going to the stack, as is likely to occur at a point where the direction of the conductor is abruptly changed.

The form of connection between the rods, the equalizing conductor 6 and the leads 7, is illustrated in Fig. 8. The upper end of the cable forming the lead 7 is untwisted, and the strands thereof wound about the equalizing conductor 6 to the right and left of the point of intersection of the lead and the equalizing conductor. A clip 8 is provided which is designed to encompass or embrace the equalizing conductor and the portions of the lead 7 wrapped thereabout, the lower portion of the clip being bifurcated to accommodate the lead cable. The rod 2 is set in the clip by means of screw threads, and the entire joint, including the lower portion of the rod 2, the clip 8 and the adjacent portions of the equalizing conductor 6 and lead lines 7 are all sweat-soldered together, forming a solid, and substantially integral joint. The lower ends of the lead cables are similarly spliced about the ground line, and the joint sweated.

In operation, in case an electrical discharge is received by any of the rods 2, it is conducted directly to the associated ground line by way of the lead 7. The equalizing conductor 6 operates to distribute the discharge among the various leads and to the various ground lines, insuring that none of the conductors shall be overcharged to a point where a charge will jump to the stack.

The leads operate, of course, to carry the charge directly from the rod to the ground line uithout subjecting it to any abrupt change of direction in which it would be likely to leave the conductor. It will be seen, therefore, that by providing the direct electrical connection between rods and ground line, and equalizing connection between the various rods and the various groundlines, I greatly increase the efiiciency of the device as a protection, and enable it to handle safely and directly such discharges as it may receive.

I am aware that minor changes may be made in the device without departing from the spirit and scope of the invention.

\Vhat I claim is:

1. An apparatus for protecting stacks "from lightning comprising the combination of a plurality of collecting rods supported upon the upper portion of the stack, an equalizing conductor connected to all of said rods, a plurality of ground lines supported on the stack, and a plurality of lead lines extending upwardly along the side of the stack from each of said ground lines and diverging gradually therefrom; each of said lead lines being connected at its lower eX- tremity to one of said ground lines, and at its upper extremity to one of said rods and said equalizing conductor at a point a substantial distance above its point of connection to the ground line, for the purpose described.

2. In an apparatus for protecting stacks from lightning, a ground line supported on the stack, a plurality of collecting rods sup- )orted on the stack and spaced apart, and a plurality of leads supported on the stack and each connected at its upper end to one of said rods and at its lower end to said ground line, the connection to the latter being at a point a substantial distance below the termini of the rods, so that the leads converge gradually from their respective rods to the ground line.

3. In an apparatus of the class described, an equalizing conductor, a grounded conductor having electrical connection therewith, a clip member having electrical connection with the equalizing'conductor and the grounded conductor at their point of connection, and a collecting rod supported by the clip.

In testimony whereof I hereunto afiix my signature in the presence of two witnesses this 11th day of February, 1915.

WILLIAM BAJOHR.

Witnesses:

M. P. SMITH, M. C. GEISSERT.

Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of Patents,

' Washington, D. 0. 

